man showing how to increase serotonin

What is Serotonin?

Serotonin is a chemical produced in the brain and intestines that is known as a neurotransmitter.  Neurotransmitters help regulate how your brain works.  Surprisingly 80-90% of your body’s level of this neurotransmitter is found in your gut.  It is known as the “happy” neurotransmitter, it elevates your mood, improves your sense of well-being and can help you feel calmer.

What are Signs of Low Serotonin?

Symptoms of low serotonin include:

How Do You Make Serotonin?

Initially, the body uses BH4 and tryptophan to make 5-HTP, through an enzyme called tryptophan hydroxylase and iron. 5-HTP is then converted to serotonin through another enzyme called aromatic l-amino acid decarboxylase.  This enzyme needs active vitamin B6, called pyridoxal-5-phosphate, to do this conversion.  Most supplements, including B complex vitamins, contain inactive B6 or pyridoxine hydrochloride, which then needs to be converted by your liver into active B6.

How Do You Get More Serotonin without Drugs?

This is a great question and also one without a definitive research-based answer.  It’s difficult to conduct research that measures the level of neurotransmitters in your brain.  We could perhaps infer from things that help us feel good, ways to increase this neurotransmitter.


Therapy helps people feel better for a reason and it may be because it helps raise their serotonin level.

Exposure to bright light

We feel better on sunny summer days than dreary winter ones.  There are animal experiments showing an increase in serotonin after exposure of the retina to bright light.


There are clear benefits to your mood from exercise. Research suggests that exercise increases brain serotonin function.


Everyone supposes that turkey dinner makes you feel sleepy because it raises your tryptophan level and therefore causes you to make more melatonin, the sleep neurotransmitter.  Tryptophan is also one of the building blocks to make serotonin.  Research does not support the idea that turkey or other tryptophan-rich foods, raise the brain level of this neurotransmitter.  Although, supplemental tryptophan or 5-HTP can.

Vitamin B6

Vitamin B6 is a building block that is used to produce serotonin.  Pyridoxal-5-phosphate is the active form of vitamin B6.  Studies on the offspring of vitamin B6 deficient mice demonstrated a down-regulation of the enzyme that is used to make serotonin (tryptophan hydroxylase).  Food sources for vitamin B6 include fish, beef liver, beef, poultry and other organ meats, potatoes and other starchy vegetables, and fruit (other than citrus).


Magnesium is also involved in the production of serotonin.  Research shows lower magnesium levels in platelets in suicidal patients with depression than in non-suicidal patients with depression.  Magnesium is present in foods like legumes, nuts, seeds, fish and leafy green vegetables.  Because there is a very high demand and the food supply is depleted in it, I recommend magnesium supplementation.


Iron is a co-factor for the enzyme that converts tryptophan to 5-HTP. Iron-rich foods include beef, poultry and leafy greens like spinach and kale.

Hormone Balance

Deficiency of testosterone, DHEAs, DHT and progesterone can all contribute to feelings of depression.  Deficiency, sudden decline of and an excess of estradiol (estrogen) are also associated with depression. Research on reproductive hormones and mental health suggest that reproductive hormones influence neurotransmitter receptors in the brain.  Estradiol has been shown to increase the rate of the enzyme that produces serotonin and decreases the rate of the enzyme that breaks it down.

A Healthy Gut

Since 80-90% of your body’s serotonin is located in the gut, having a healthy gut may be crucial to healthy serotonin production.  Good bacteria in the gut help to keep the gut healthy and may influence serotonin production.  One study on probiotics found that after probiotic supplementation, there was a significant increase in the concentration of serum serotonin and a decreased level of tryptophan in plasma.  Probiotics are found in fermented foods like miso, Kim chi, yogourt, raw sauerkraut and kefir.

Active Folic Acid or L-5MTHF

5-MTHF deficiency decreases SAMe in the rat brain.  SAMe acts as an antidepressant in humans.  There is a genetic mutation called an MTHFR mutation in which people have difficulty producing L-5MTHF from food or supplemental folic acid.  These people benefit from avoiding supplements with inactive folic acid (referred to as folate or folic acid) and only using supplemental folic acid in the form of 5MTHF or L-5MTHF.

As a licensed naturopathic doctor, with a focus on hormone balance, I often find patients’ mood improves as their hormones achieve a better balance.  If you are struggling with depression and feelings of unhappiness, see one of our naturopathic doctors and/or our psychotherapist at Forces of Nature.

For help with this or any other health problem, book an appointment here or call the office for more information at 416-481-0222.

by Dr. Pamela Frank, BSc(Hons), ND

Increasing Serotonin Research

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Leahy LG. Vitamin B Supplementation: What’s the Right Choice for Your Patients? J Psychosoc Nurs Ment Health Serv. 2017 Jul 1;55(7):7-11. doi: 10.3928/02793695-20170619-02.

Almeida MR, Mabasa L, Crane C, Park CS, Venâncio VP, Bianchi ML, Antunes LM. Maternal vitamin B6 deficient or supplemented diets on expression of genes related to GABAergic, serotonergic, or glutamatergic pathways in hippocampus of rat dams and their offspring. Mol Nutr Food Res. 2016 Jul;60(7):1615-24. doi: 10.1002/mnfr.201500950. Epub 2016 Mar 29.

Ruljancic N, Mihanovic M, Cepelak I, Bakliza A, Curkovic KD. Platelet serotonin and magnesium concentrations in suicidal and non-suicidal depressed patients. Magnes Res. 2013 Jan-Feb;26(1):9-17. doi: 10.1684/mrh.2013.0332.

Joel C. Bornstein. Serotonin in the Gut: What Does It Do? Front Neurosci. 2012; 6: 16.

Modulation of Tryptophan/Serotonin Pathway by Probiotic Supplementation in Human Immunodeficiency Virus-Positive Patients: Preliminary Results of a New Study Approach. Int J Tryptophan Res. 2017 May 30;10:1178646917710668. doi: 10.1177/1178646917710668. eCollection 2017.

Simon N. Young Folate and depression—a neglected problem. J Psychiatry Neurosci. 2007 Mar; 32(2): 80–82.

Rybaczyk, L.A., et al. (2005). An overlooked connection: serotonergic mediation of estrogen-related physiology and pathology. BMC Women’s Health, 5:12.

Luine,V.N., et al. (1983). Gonadal hormone regulation of MAO and other enzymes in hypothalamic areas. Neuroendocrinology.36(3):235-241.